Apparatus for examining brain injury, method of making and method of using the same

ABSTRACT

A test apparatus or system for testing impact induced brain trauma a method of making and a method using the same are provided. The system includes a head model, which includes a skull component, a brain component, and a fluid component. The skull component has a wall defining an interior chamber. The brain component includes a gel material and is disposed within the interior chamber. The fluid component is disposed inside the interior chamber. The system may also include a fluid tank fluidly coupled with the skull component and configured to provide the fluid component into the interior chamber. The head model may further include a layer of porous media disposed between the brain component and the interior wall surface of the skull component. The system may include at least one impact element for providing an impact on the head model. The impact is translational or rotational or both.

PRIORITY CLAIM AND CROSS-REFERENCE

This application claims the benefit of U.S. Provisional Application No.62/621,854, filed Jan. 25, 2018, which application is expresslyincorporated by reference herein in its entirety.

FIELD OF THE INVENTION

The disclosure relates to study and detection of brain injury generally.More particularly, the disclosed subject matter relates to a testapparatus or system for measuring the effect of a head impact on abrain, a method of making and a method of using the test apparatus.

BACKGROUND

Chronic traumatic encephalopathy (CTE) is a progressive degenerativedisease resulting from a head trauma and particularly a history ofrepetitive head trauma. Military personnel may be exposed to blasts andother head impacts, which may lead to development of CTE. Otherenvironments where people may be subjected to head trauma include thehealth care industry, and industrial environments such as in a factoryor construction site. Athletes participating in contact sports such asfootball, soccer, rugby and boxing incur repetitive head trauma that hasbeen shown to lead to the development of CTE in some individuals. CTEmay result from symptomatic concussions as well as sub-concussive headtrauma. Many athletes may experience frequency sub-concussive headtrauma during participation in a contact sport and never have asymptomatic concussion. These athletes may still develop CTE. The effectof these frequent head impacts is a growing concern.

CTE may result from repetitive damage to axons in the brain, such asshearing caused by high acceleration of the brain tissue. Highacceleration is caused by rapid head velocity change, such as thatcaused by an impact to the head. Axons connect neurons in the brain.Damage to the axons can result in immediate effects and/or delayedeffects, such as CTE. Brain injury, such as axonal shearing, may createneurochemical and neurometabolic cascade effects. Even mild trauma tothe brain can result in neuronal depolarization, which leads to neuronaldischarge and the release of neurotransmitters and increased extracellular potassium (K⁺). This may be followed by an increased glucosedemand and metabolism (hyperglycolysis) and a resultant relativeischemia from reduced cerebral blood flow. Axonal injury may also resultfrom an influx of extra cellular calcium that reduces cerebral bloodflow through vasoconstriction, and the release of oxygen free radicals.These neurochemical and neurometabolic effects from even mild headtrauma may result in the development of CTE.

SUMMARY OF THE INVENTION

The present disclosure provides a test apparatus or system for testingimpact induced brain trauma or impairment, a method of making and amethod using the same.

In accordance with some embodiments, the test apparatus or systemcomprises a head model. Such a head model comprises a skull component, abrain component, a fluid component. The skull component has a walldefining an interior chamber. The wall has an exterior wall surface andan interior wall surface. The brain component is disposed within theinterior chamber, and comprises a gel material such as a polymeric gelor biological material for simulating brain tissues. The fluid componentis disposed inside the interior chamber. In some embodiments, the systemcomprises a fluid tank, which is fluidly coupled with the skullcomponent and is configured to provide the fluid component into theinterior chamber.

In some embodiments, the skull component is made of a rigid andtransparent material. The brain component may be in a spherical or anyother suitable shape. In some embodiments, the brain component is shapedand sized to simulate a brain of a human subject.

In some embodiments, the fluid component has at least one portiondisposed between the brain component and the interior wall surface ofthe skull component. The fluid tank is connected with the skullcomponent through a tube. The fluid tank is configured to adjust apressure of the fluid component inside the interior chamber in someembodiments.

In some embodiments, the head model further comprises a layer of porousmedia disposed between the brain component and the interior wall surfaceof the skull component. The layer of porous media comprises the fluidcomponent disposed inside the porous media, and may be soaked with thefluid component.

In some embodiments, the system may include at least one impact elementconfigured to provide an impact on the head model. The impact istranslational or rotational or both. In some embodiments, the at leastone impact element comprises a rotor coupled with the head model toprovide a rotational impact on the head model.

The system may further comprise one or more sensors embedded inside orpartially attached with the wall of the skull component. For example,the one or more sensors may be selected from the group consisting of apressure sensor, a displacement sensor, an accelerometer, and acombination thereof. The system may also comprise a camera configured totake a plurality of images showing one or more components inside theinterior chamber. The system may also include a computer and a computerprogram configured to analyze data from the one or more sensors and theplurality of the images for detecting impact induced brain trauma.

In another aspect, the present disclosure provides a method of formingthe test apparatus or system as described herein. Such a methodcomprises forming a head model. The step of forming the head modelcomprises providing a skull component, having a wall defining aninterior chamber, forming a brain component comprising a gel materialfor simulating brain tissues, placing the brain component within theinterior chamber, and supplying a fluid component into the interiorchamber from a fluid tank disposed outside the skull component. Thefluid tank is fluidly coupled with the skull component so as to providethe fluid component into the interior chamber with a controlledpressure.

In some embodiments, the brain component is formed through stepsincluding: three-dimensionally (3-D) printing a skull model based onanatomical data from computed topography (CT) scan of a head of a humansubject, forming a negative casting mold based on the skull model, andcasting the brain component inside the negative casting mold. In someembodiments, the data from a CT scan can be used to design a mold on acomputer. The mold can be then made without 3D printing a skull modelfirst.

In some embodiments, a layer of porous media may be placed between thebrain component and the interior wall surface of the skull component. Insome embodiments, at least one impact element may be also provided forgiving an impact on the head model. The impact is translational orrotational or both.

In another aspect, the present disclosure provides a method of using asystem for testing impact induced brain trauma as described herein. Sucha method comprises a step of providing an impact on the head model fromat least one impact element. The impact is translational or rotationalor both. In the system, the head model may include a layer of porousmedia disposed between the brain component and the interior wall surfaceof the skull component. In some embodiments, a rotational impact on thehead model is provided by a rotor in the at least one impact element.The rotor is coupled with the head model. In some embodiments, such amethod includes steps of collecting data from one or more sensorsembedded inside or partially attached with the wall of the skullcomponent, taking a plurality of images through a camera to show one ormore components inside the interior chamber, and analyzing the data andthe plurality of images using a computer and a computer program so as todetecting impact induced brain trauma.

The present disclosure provides an approach to examine the flow andpressurization of the cerebrospinal fluid flow (CSF) in the subarachnoidspace (SAS) as the head is imposed to sudden external impacts. The testapparatus or system includes an improved head model to better understandthe mechanism of concussive and sub-concussive brain injuries, and toprovide guidance for the prevention of such injuries. For example, theCSF flow through the soft, porous arachnoid trabeculae (AT) in the SAS,and both translational and rotational impact are considered. Withconsideration of the complicated nature of the biological system, abiomimetic approach is used to investigate the mechanism of braininjury.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is best understood from the following detaileddescription when read in conjunction with the accompanying drawings. Itis emphasized that, according to common practice, the various featuresof the drawings are not necessarily to scale. On the contrary, thedimensions of the various features are arbitrarily expanded or reducedfor clarity. Like reference numerals denote like features throughoutspecification and drawings.

FIG. 1A is a plan view illustrating a first half (e.g., a bottom piece)of an exemplary mold for casting an artificial brain component inaccordance with some embodiments.

FIG. 1B is a plan view illustrating a second half (e.g., a top piece) ofan exemplary mold for casting an artificial brain component inaccordance with some embodiments.

FIG. 2A is a sectional view illustrating the first half of the exemplarymold as shown in FIG. 1A.

FIG. 2B is a sectional view illustrating the second half of theexemplary mold as shown in FIG. 1B.

FIG. 3 is a sectional view illustrating the exemplary mold when thefirst half as shown in FIG. 2A and the second half as shown in FIG. 2Bare closed in accordance with some embodiments.

FIG. 4 is a flow chart illustrates an exemplary method for casting anartificial brain component in accordance with some embodiments.

FIG. 5 is a schema illustrating different test apparatus for testingtranslational and rotational impacts of head on brains in accordancewith some embodiments. Each test apparatus is illustrated in moredetails in one respective figure of FIGS. 6-13, which are sectionalviews.

FIG. 6 illustrates an exemplary apparatus including artificial brain ina shape of an inner sphere for testing translational impact inaccordance with some embodiments.

FIG. 7 illustrates an exemplary apparatus including head surrogate fortesting translational impact in accordance with some embodiments.

FIG. 8 illustrates an exemplary apparatus including artificial brain ina shape of an inner sphere and porous media for testing translationalimpact in accordance with some embodiments.

FIG. 9 illustrates an exemplary apparatus including head surrogatehaving porous media for testing translational impact in accordance withsome embodiments.

FIG. 10 illustrates an exemplary apparatus including artificial brain ina shape of an inner sphere for testing rotational impact in accordancewith some embodiments.

FIG. 11 illustrates an exemplary apparatus including head surrogate fortesting rotational impact in accordance with some embodiments.

FIG. 12 illustrates an exemplary apparatus including artificial brain ina shape of an inner sphere and porous media for testing rotationalimpact in accordance with some embodiments.

FIG. 13 illustrates an exemplary apparatus including head surrogatehaving porous media for testing rotational impact in accordance withsome embodiments.

FIG. 14 is a flow chart illustrating an exemplary method of making anexemplary system in accordance with some embodiments.

FIG. 15 is a flow chart illustrating an exemplary method of using anexemplary system in accordance with some embodiments.

DETAILED DESCRIPTION

This description of the exemplary embodiments is intended to be read inconnection with the accompanying drawings, which are to be consideredpart of the entire written description. In the description, relativeterms such as “lower,” “upper,” “horizontal,” “vertical,”, “above,”“below,” “up,” “down,” “top” and “bottom” as well as derivative thereof(e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should beconstrued to refer to the orientation as then described or as shown inthe drawing under discussion. These relative terms are for convenienceof description and do not require that the apparatus be constructed oroperated in a particular orientation. Terms concerning attachments,coupling and the like, such as “connected” and “interconnected,” referto a relationship wherein structures are secured or attached to oneanother either directly or indirectly through intervening structures, aswell as both movable or rigid attachments or relationships, unlessexpressly described otherwise.

For purposes of the description hereinafter, it is to be understood thatthe embodiments described below may assume alternative variations andembodiments. It is also to be understood that the specific articles,compositions, and/or processes described herein are exemplary and shouldnot be considered as limiting.

In the present disclosure the singular forms “a,” “an,” and “the”include the plural reference, and reference to a particular numericalvalue includes at least that particular value, unless the contextclearly indicates otherwise. When values are expressed asapproximations, by use of the antecedent “about,” it will be understoodthat the particular value forms another embodiment. As used herein,“about X” (where X is a numerical value) preferably refers to ±10% ofthe recited value, inclusive. For example, the phrase “about 8”preferably refers to a value of 7.2 to 8.8, inclusive. Where present,all ranges are inclusive and combinable. For example, when a range of “1to 5” is recited, the recited range should be construed as includingranges “1 to 4”, “1 to 3”, “1-2”, “1-2 & 4-5”, “1-3 & 5”, “2-5”, and thelike. In addition, when a list of alternatives is positively provided,such listing can be interpreted to mean that any of the alternatives maybe excluded, e.g., by a negative limitation in the claims. For example,when a range of “1 to 5” is recited, the recited range may be construedas including situations whereby any of 1, 2, 3, 4, or 5 are negativelyexcluded; thus, a recitation of “1 to 5” may be construed as “1 and 3-5,but not 2”, or simply “wherein 2 is not included.” It is intended thatany component, element, attribute, or step that is positively recitedherein may be explicitly excluded in the claims, whether suchcomponents, elements, attributes, or steps are listed as alternatives orwhether they are recited in isolation.

The present disclosure provides a test apparatus or system for testingimpact induced brain trauma or impairment, a method of making and amethod of using the same. Each test apparatus or system has a respectivehead model, which includes at least a skull component and a braincomponent.

Unless expressly indicated otherwise, references to “a skull component”made herein will be understood to encompass a structure having a wallfor forming an enclosure or interior cavity and including a materialhaving density and mechanical strength close to or the same as those ofa human skull. Such a material might be rigid. A skull component may bein a spherical or any other shape. In some embodiments, it is shaped andsized to simulate or mimic a skull of a human subject.

Unless expressly indicated otherwise, references to “a brain component”made herein will be understood to encompass a structure made of a softmaterial having density and mechanical strength close to those of ahuman brain. A brain component may be in a spherical or any other shape.In some embodiments, it is shaped and sized to simulate or mimic a brainof a human subject.

Unless expressly indicated otherwise, references to “a fluid component”made herein will be understood to encompass a fluid or a solution, whichmight be aqueous. Such a fluid may have a density or a compositionsimilar to that of cerebrospinal fluid. In some embodiments, water or asaline solution is used.

Unless expressly indicated otherwise, references to “an impact element”made herein will be understood to encompass a structure configured toprovide an impact onto a head model. An impact element may be configuredto simulate any number of different types of impact surfaces andorientations. In some embodiments, such an impact is translational,rotational, or both.

An impact element may be configured to simulate any number of differenttypes of impact surfaces and orientations. For example, an impactelement may include or simulate concrete, the ground, metal, a bat, aball, a vehicle, a person's head (e.g., to simulate a head impact duringa soccer game), or other impact element. The impact element can beprecisely controlled by an actuator to provide consistent impacts on thesimulated head model, the consistent impacts having consistent physicalparameters, including but not limited to impact velocity and/oracceleration. The actuator may be controlled to move the impact elementat any suitable velocity and/or acceleration throughout the stroke ortravel distance of the impact element. As described herein, the impactelement may be controlled to retract back quickly after providing theimpact directly or indirectly to the head model. An impact simulator maycomprise one, two or more impact elements configured to impact the headmodel at substantially the same time, or in rapid succession, forexample, or at different locations.

In the drawings, like items are indicated by like reference numerals,and for brevity, descriptions of the structure, provided above withreference to the preceding figures, are not repeated. The methoddescribed in FIG. 4 are described with reference to the exemplarystructure described in FIGS. 1-3. FIGS. 6-13 describes in detail thetest apparatus or systems having a respective head model illustrated inthe scheme of FIG. 5. In each model, other components may not be shown.For example, one or more head exterior components for simulating hairand skin may extend around the perimeter of each skull component. FIG.14 illustrates an exemplary method of making a system comprising eachhead model as described in FIGS. 6-13. FIG. 15 illustrates an exemplarymethod of using a system comprising each head model as described inFIGS. 6-13.

1. Brain Component:

FIGS. 1A-1B, 2A-2B, 3 and 4 describe an exemplary mold and an exemplarymethod for forming a brain component.

Referring to FIGS. 1A-1B and 2A-2B, an exemplary mold includes a firsthalf of mold 10 such as a bottom mold piece and a second half of mold 20such as a top mold piece. FIGS. 1A and 2A are plan views while FIGS. 1Band 2B are sectional views along lines A-A′ and B-B′, respectively. Sucha mold is used for forming an artificial brain matter or a braincomponent 30. The two halves of mold 10, 20 may be made of a metal or apolymer such as a thermoset acrylic polymer, or any other suitablematerial.

Referring to FIGS. 1A and 2A, the first half of mold 10 includes a firstmold plate 12 defining a first mold cavity 14, which may have surfacefeatures 16 reflecting and simulating surface morphology of a brain of ahuman subject. The first half of mold 10 may also define holes 18 forbolts in each corner, and may be so configured that a support 19 for abrain component can be inserted into the first mold cavity 14 during amolding process.

Referring to FIGS. 1B and 2B, the second half of mold 20 includes asecond mold plate 22 defining a second mold cavity 24, which may havesurface features 26 reflecting and simulating surface morphology of abrain of a human subject. The second half of mold 20 may also defineholes 28 for bolts 29 in each corner. The bolts 29 can be inserted intothe holes 18 of the first half of mold 10 when the two halves of mold10, 20 are assembled together during a molding process.

Referring to FIG. 3, when the two halves of mold 10, 20 are assembledtogether, a brain component 30 can be molded or casted by using asuitable material fed into the mold cavity. In some embodiments, thebrain component 30 may have a spherical shape. In some embodiments, thebrain component 30 may have a size, a shape, and surface features 32simulating a brain of a human subject. The brain component 30 maycomprise a gel material such as a polymeric gel or biological materialfor simulating brain tissues.

Referring to FIG. 4, an exemplary method 200 is described for forming abrain component 30 in accordance with some embodiments. At step 202, askull model may be made through three-dimensional (3-D) printing basedon anatomical data from computed topography (CT) scan of a head of ahuman subject. At step 204, a negative casting mold is made based on theskull model. Such a mold may include two mold pieces 12, 22 (i.e. twohalves) as described above. In some embodiments, the data from a CT scancan be used to design a mold on a computer. The mold can be then madewithout the step of 3D printing a skull model first. In someembodiments, the mold has a size of a human brain based on a brainanatomical model. The mold may be made of a thermoset acrylic polymer insome embodiments.

At step 206, the brain component 30 is casted or molded inside thenegative casting mold. In some embodiments, the material for the braincomponent 30 is a polymeric gel such as a silicone gel. The silicone gelmay be crosslinkable through a platinum-catalyzed curing system, and mayhave a shore 00 hardness in a range of from 10 to 50. Such silicone gelmaterials is available under trademark ECOFLEX® from Smooth-On Companyin Pennsylvania, USA. For example, two types of silicone gel materialsECOFLEX® 00-30 (having shore 00 hardness of 30) and ECOFLEX® 00-20(having shore 00 hardness of 20) were used. Each of these two siliconegel materials was poured into the mold (FIG. 3) to cast a braincomponent 30.

In the step 206, the following procedures were followed in someexperimental trials. A silicone material and a catalyst are mixed. Amold release is sprayed onto the internal surfaces of the mold pieces12, 22. The support 19 to the brain component 30 such as a neckcomponent, which is a solid structure, is put into the mold. The moldpieces 12, 22 are assembled together. In some embodiments, any possiblegap between can be sealed by using clay. After fully mixed, the siliconematerial is degassed in a vacuum box to avoid formation of cavities inthe resulting brain component 30. The silicone material is poured intothe mold through a feeding port. Vacuum is applied to extract airpossibly trapped in the mold while the mold is shaken slightly. Thesilicone material is cured overnight in the mold. A brain component 30made of silicone gel is removed from the mold.

Tensile tests were performed to examine tensile properties of thesilicone gel materials including ECOFLEX® 00-30 and ECOFLEX® 00-20. Flatsilicone gel sheets were obtained by casting in a flat mold. Thedimensions of the sheets were 15.2 cm×26 cm×0.2 cm. Due to highflexibility of the materials, it is not feasible to prepare an idealdog-bone shaped tensile specimen using machining methods. Therefore, asteel hole-punch (7.9 mm in diameter) was used to prepare quasi-dog-bonespecimens. An MTS BIONIX® universal testing machine with a load cell of100 N were used to conduct the tensile tests. The crosshead speed of theMTS machine was set at 10 mm per second. Strain gages could not beattached to the specimens, so an alternative approach was used toestimate the strain reading. For all the tests, the initial distancebetween the upper and lower grips was kept at 11 mm, and was adopted asthe original gage length to calculate the strains for all the tensilespecimens. The measured maximum tensile strength of silicone sheets madeof ECOFLEX® 00-30 and ECOFLEX® 00-20 was about 0.9 MPa and 0.66 MPa,respectively. The measured Young's modulus of silicone sheets made ofECOFLEX® 00-30 and ECOFLEX® 00-20 was about 0.13 MPa and 0.068 MPa,respectively.

Soft silicone gel materials are described for illustration purpose. Anyother suitable materials may be used to cast or mold a brain surrogate.

2. Head Models and Resulting System:

In the present disclosure, a novel approach is proposed to examine theflow and pressurization of the cerebrospinal fluid flow (CSF) in thesubarachnoid space (SAS) when the head is exposed to sudden externalimpacts. The goal is to better understand the mechanism of concussiveand sub-concussive brain injuries, and to provide guidance for theprevention of such injuries. The brain can be treated as a soft tissuebathed in the fluid (i.e. CSF), which is enclosed by a rigid structure,i.e., a skull. The brain concussion is a type of brain injury within anintact skull. The concussive and sub-concussive injuries occur as aresult of a series of fluid-structure-interactions (FSI) between therigid skull, the CSF and the soft brain matter. The deformation of thebrain is a main reason for the brain concussion. The strain of the braintissue needs to be used as an indicator for the brain injury. The impactduration is very short and thus the FSI is extremely transient. The CSFflow through the soft, porous arachnoid trabeculae (AT) in thesubarachnoid space (SAS) plays a crucial role in this process.Considering the complicated nature of the biological system, abiomimetic approach is proposed herein to investigate the mechanism ofbrain injury.

The present disclosure provides a test apparatus or system including ahead model 50. The head model 50 includes a brain component 30, a skullcomponent 82, and a fluid component 84. In some embodiments, the headmodel 50 further includes a layer of porous media 102 disposed betweenthe brain component 30 and the skull component 82. Such a system mayinclude at least one impact element 70 configured to provide an impacton the head model. The impact is translational or rotational or both.

FIG. 5 illustrates different head models and the resulting systems,which are described in detail in FIGS. 6-13. Two types of impacts areconsidered, translational and rotational. The at least one impactelement 70 may include a linear impactor 78 to provide translationimpact, and/or a rotor 122 to provide rotational impact. As shown inSections 1A, 1B, 2A, and 2B in the chart of FIG. 5, a linear impactor 78may be used. As shown in Sections 3A, 3B, 4A, and 4B in the chart ofFIG. 5, a rotor 122 may be used. Two types of experimental setups areconsidered, including a spherical apparatus (illustrated in Sections1A-1B and 3A-3B of FIG. 5), and a simulated head surrogate (illustratedin Sections 2A-2B and 4A-4B of FIG. 5). Both have the testing materialbathed in a liquid environment. Various soft materials are considered tosimulate the soft brain matter, from artificial gel type of softmaterials to a real porcine brain. The artificial gel like materials maybe coated with porous media 102 (as illustrated in Sections 1B, 2B, 3Band 4B of FIG. 5) for studying the role of arachnoid trabeculae (AT) intransmitting impact on a head.

Referring to FIG. 6, an exemplary apparatus 80 is used in someembodiments. The exemplary apparatus 80 includes an artificial braincomponent 30 in a spherical shape in a head model 50. The sphericalshape is for illustration only. The brain component 30 may be in anyother suitable shape.

The head model 50 is disposed on a support 62 with a slider 62 or otheraccessory fixtures. The slider 62 is used to support the skull component82 in the head model 50 and allow the skull component 82 to movelinearly.

The skull component 82 has a wall 83 defining an interior chamber orcavity 85. The wall 83 has an exterior wall surface 83 a and an interiorwall surface 83 b. In some embodiments, the skull component 82 is madeof a rigid and transparent material. The brain component 30 is disposedwithin the interior chamber 85, and includes a gel material such as apolymeric gel or biological material for simulating brain tissues.

The brain component 30 can be made of various materials including, butnot limited, to casted artificial brain matter (e.g., silicone gel), aporcine brain, and a brain component made of chicken eggs. Themechanical behavior (e.g., stiffness) of a porcine brain as well as theartificial brain matter can be characterized using an atomic forcemicroscope (AFM). Considering the density and other properties of thebrain vary with age, gender and many other reasons, the choice ofmaterials for the brain component 30 provides a full spectrum to examinethe influence from different impact processes.

The fluid component 84 is disposed inside the interior chamber 85. Insome embodiments, the system includes a fluid tank 68, which is fluidlycoupled with the skull component 82 through a tube 69 and is configuredto provide the fluid component 84 into the interior chamber 85. In someembodiments, the fluid component 84 has at least one portion disposedbetween the brain component 30 and the interior wall surface 83 b of theskull component 82. A gap exists between the brain component 30 and theskull component 82 in some embodiments.

Different types of fluid can be filled into the tank 68 to simulate theCSF. The density and other properties of CSF vary with age, gender andmany other reasons. The choice of liquid for the fluid component 84provides a full spectrum to examine the influence from an impactprocess. The fluid tank 68 may be configured to adjust a pressure of thefluid component 84 inside the interior chamber 85 in some embodiments.In some embodiments, the pressure of the fluid component 84 may becontrolled via a U-tube type setup with the liquid tank 68. The ambientpressure inside the tank 68 and the height of the tank 68 can be variedleading to different liquid pressures inside the container.

The system or apparatus 80 may include a linear impactor 78 to providetranslational impact on the head model 50. The linear impactor 78 isconfigured to create a sudden translational impact on the skullcomponent 82, which is further transmitted to the brain component 30 viathe fluid gap of the fluid component 84 between the brain component 30and the skull component 82.

The system or apparatus 80 may further include one or more sensorsembedded inside or partially attached with the wall 83 of the skullcomponent 82. For example, the one or more sensors may be selected froma pressure sensor 72, a displacement sensor 74, an accelerometer 75, anda combination thereof. A laser sensor 66 may be also used to monitor themovement of the head model 50. The experimental setup uses instrumentedsensors to measure the motion, velocity and the acceleration of theskull component 82, the pressure distribution of fluid, as well as themotion and deformation of the brain component 30 (FIG. 6).

The system or apparatus 80 may also include a high-speed camera 76configured to take a plurality of images showing one or more componentsinside the interior chamber 85. The outer shell of the skull component82 is transparent to allow direct visualization of the motion of theinner sphere using such the high-speed camera 76. The motion anddeformation of the brain component 30 will also be captured by ahigh-speed camera.

The system may also include a computer (not shown) with a computerprogram configured to analyze data from the one or more sensors and theplurality of the images for detecting impact induced brain trauma orimpairment.

Referring to FIG. 7, an exemplary apparatus 90 is used in someembodiments. The exemplary apparatus 90 is the same as the exemplaryapparatus 80 except the shape of the head model 50 (i.e., a headsurrogate) and related neck support. The components having the samereference numerals are described in FIG. 6. The exemplary apparatus 90includes a head model 50 and an artificial brain component 30 simulatingthose of a human subject. The head model 50 and the brain component canbe patient-specific. Similar to the exemplary apparatus 80, theexemplary apparatus 90 is also used for testing translational impact inaccordance with some embodiments.

A biomimetic approach is used to model the human brain. The systemincludes a skull component 84, a molded brain component 30, supportingstructure, and the intracranial fluid, as shown in FIG. 7. As describedin FIGS. 1-4, precise anatomical data from a CT scan is used to 3-Dprint a skull component 82 and form the negative casting mold for thebrain component 30. The skull component is transparent to allowinspection of the motion and deformation of the brain matter using ahigh-speed camera. The artificial brain-like material such as siliconegel is used to perform the test, and is casted by the negative brainmold using the casting approach as described in FIGS. 1-4. In someembodiments, a porcine brain can be tested as well. Due to its softnature, instead of using electrical sensors, the motion of the realbrain can be measured by a high speed camera.

As illustrated in FIG. 7, a support 19, such as an artificial hybridneck used in dummy crash testing, is used to support the head model 50including the casted brain component 30 and the skull component 82. Thehead model 50 may be coupled to a mount to restrain and providestability during an impact test. In some embodiments, a neck spring maycouple the head model 50 to a mount and may be flexible to enable somedeflection and movement of the head model 50 during an impact test. Aneck spring may be made out of a flexible material that can bephysically returned to an original position. A neck spring may includeone or more springs. The impact element 78 may be configured to impactthe head model and then quickly retract, thereby allowing the head model50 to spring back or recoil from the impact. This simulates real worldimpacts or accelerations, such as a rear-end car accident.

The skull component 82 is instrumented with an accelerometer 75 tomeasure its velocity and acceleration. Displacement sensor 66 mounted ona frame measures the motion of the skull component 82 due to impacts.Displacement sensor 74 mounted on the skull will measure theinstantaneous variation of the subarachnoid space (SAS) due to themotion of the brain matter 30 relative to the skull component 82. Agyroscope placed at the location of the medulla oblongata provides datafor the angular velocity of the head surrogate. Multiple pressuresensors 72 mounted on the skull or inside the skull capture thesimulated pressure response of the CSF inside the SAS.

Referring to FIG. 8, an exemplary apparatus 100 is illustrated. Theexemplary apparatus 100 is the same as the exemplary apparatus 80 exceptthat the exemplary apparatus 100 includes a layer of porous media 102for simulating porous arachnoid trabeculae (AT). In some embodiments,the head model 50 further includes a layer of porous media 102 disposedbetween the brain component 30 and the interior wall surface of theskull component 82. The layer of porous media 102 includes the fluidcomponent 84 disposed inside the porous media 102, and may be soakedwith the fluid component 84. In some embodiments, the layer of porousmedia 102 is made any suitable material having damping properties. Insome embodiments, the layer of porous media 102 is made of asupermolecular polymer having a net or net-like structure. Such apolymer may be electrospun.

In order to examine the effect of the porous media, the skull component82 is filled with a soft fibrous porous structure with variablepermeability (i.e., the layer 102). Various functionalizedsupramolecular porous layers (SML) are prepared using an electrospinningprocess. An electrospinning system includes a power supply, a syringearray and syringe pump, two rollers and a controller. Solutions ofpolymers such as poly (vinylidene fluoride), poly (vinylidenefluoride-co-hexafluoro-propylene), polyvinyl pyrrolidine, polylacticacid polyacrylonitrile, poly (ethylene glycol), or any other polymerscan be sprayed on a conveyer belt. The speed and spray frequency arecontrolled to provide SML with various pore size, stiffness, andthickness. The fiber diameter and/or thickness of the SML can betailored and characterized by scanning electronic microscopy (SEM). TheSML as the layer of porous media 102 can be disposed in the skullcomponent 82 to allow for examination of the transient flow behavior inan enclosed skull component 82 filled with porous media 102.

Referring to FIG. 9, an exemplary apparatus 110 is illustrated. Theexemplary apparatus 110 is the same as the exemplary apparatus 90 exceptthat the exemplary apparatus 100 includes a layer of porous media 102 asdescribed in FIG. 8. In some embodiments, the brain matter or component30 is coated with functionalized porous SML to simulate the porousarachnoid trabeculae (AT). Comparisons of the response of the brainmatter to the same external impacts can be made between SML coated andno-SML coated brain models. The porosity, permeability and fiberstiffness of the SML can be varied, and the effect of disturbance can beevaluated in the structure of the AT in the case of concussive orsub-concussive brain injury.

Parametric studies can be performed to examine the response of the samebrain component 30 to different impact conditions, or the response ofdifferent brain components 30 to the same impact condition. Thevariations of the parameters include, the mechanical properties of theskull component 82 and the brain component 30, and the mechanical andtransport properties of the SML.

FIGS. 10-13 illustrate four exemplary apparatuses 120, 130, 140 and 150for testing rotational impact in accordance with some embodiments. Theexemplary apparatuses 120, 130, 140 and 150 have the same head models asillustrated in FIGS. 6-9, respectively. As illustrated in FIGS. 10-13,in some embodiments, the at least one impact element 70 includes a rotor122 coupled with the head model 50 (e.g., through a rod 124) to providea rotational impact on the head model 50. In some embodiments, arotational impact is more important than a translational impact becauserotational impacts tend to result in more extensive brain injury. Therod 124 may be coupled with the head model 50 and a supporting stand ora bearing system 125 in some embodiments. The bearing system 125 is usedto support the skull component 82 allowing the skull component 82 torotate.

Referring to FIG. 10, the head model 50 is the same as that described inFIG. 6, and comprises an artificial brain component 30 in a sphericalshape. A rotational impact plays a significant role in concussive orsub-concussive brain injury. To reveal the intrinsic characteristics ofthe CSF flow during the rotational impact, an experimental setup isdesigned with a spherical ball bathed in a liquid environment andenclosed in a container. The rotor 122, which may be run by a motor, isconfigured to create rotational accelerations/decelerations to the skullcomponent 82, which is further transmitted to the inner sphere via thefluid gap (i.e. the fluid component 84) between the brain component 30and the skull component 82. The frequency, magnitude and extent (e.g.,in terms of amount of rotation) of the rotational impact can be varied.The skull component 82 is transparent to allow direct visualization ofthe motion of the brain component 30 using a high-speed camera.

Referring to FIG. 11, in the apparatus 130, the head model 50 is thesame as that described in FIG. 7, and comprises an artificial braincomponent 30 shaped and sized to simulate a brain of a human subject.The heard model or surrogate is used for testing rotational impact asdescribed in FIG. 10. A biomimetic approach is used to model therotational impact on the brain surrogate. The apparatus 130 includes arotor 122 as a rotational impactor and a bearing system 125 as describedabove. As described in FIGS. 1-4, precise anatomical data from CT scanis used to 3-D print a skull component 82 and to form the negativecasting mold for the brain component 30 in some embodiments. A porcinebrain can also be used in some embodiments. The apparatus 130 is alsoinstrumented with various sensors as described in FIG. 7. For example, adisplacement sensor mounted on the skull component 82 can measure theinstantaneous variation of the SAS due to the motion of the brain matterrelative to the skull. A gyroscope placed at the location of the medullaoblongata provides data for the angular velocity of the head surrogate.Multiple pressure sensors mounted on the skull component 82 capture thesimulated pressure response of the CSF inside the SAS.

Referring to FIG. 12, an exemplary apparatus 140 is illustrated. Theexemplary apparatus 140 is the same as the exemplary apparatus 120 (FIG.10) except that the exemplary apparatus 140 includes a layer of porousmedia 102 for simulating porous arachnoid trabeculae (AT) as describedabove.

Referring to FIG. 13, an exemplary apparatus 150 is illustrated. Theexemplary apparatus 150 is the same as the exemplary apparatus 130 (FIG.10) except that the exemplary apparatus 150 includes a layer of porousmedia 102 for simulating porous arachnoid trabeculae (AT) as describedabove.

3. Method of Making and Method of Using the System

FIG. 14 illustrates an exemplary method 300 of making an exemplarysystem as described in accordance with some embodiments. The method 300comprises forming a head model, including steps 310, 320, 330, 340 and350 in FIG. 14 in some embodiments. In step 310, a skull component 82having a wall defining an interior chamber is provided. At step 320, abrain component 30 is formed. For example, the brain component 30 can bemade using the exemplary method 200 as described in FIGS. 1-4.

At step 330, the brain component 30 is placed within the interiorchamber or cavity 85. At step 340, a fluid component 84 is supplied intothe interior chamber 85. In some embodiments, the method 300 furthercomprises coupling a fluid tank 68 having the fluid component 84 withthe skull component 82 so as to provide the fluid component 84 into theinterior chamber 85 with a controlled pressure.

At step 350, in some embodiments, a layer of porous media 102 may beoptionally placed between the brain component 30 and the interior wallsurface of the skull component 82. In some embodiments, the step ofproviding a layer of porous media 102 occurs after step 320 and beforestep 330. Step 350 occurs at the same time as step 330. After the braincomponent 30 is formed at step 320. The brain component 30 is thencoated with porous media 102 and then placed inside the skull component82. The fluid component 84 is supplied into the interior chamber 85.

At step 360, at least one impact element 70 is provided for giving animpact on the head model. The impact is translational or rotational orboth as described above.

FIG. 15 illustrates an exemplary method 400 of using an exemplary systemas described for testing impact induced brain trauma in accordance withsome embodiments. Referring to FIG. 15, at step 410, an impact on thehead model 50 is provided from at least one impact element 70. Theimpact is translational or rotational or both as described. In someembodiments, in the system such as those described in FIGS. 8-9 and12-13, the head model 50 may include a layer of porous media 102disposed between the brain component 30 and the interior wall surface ofthe skull component 82.

In some embodiments, a rotational impact on the head model 50 isprovided by a rotor 122 in the at least one impact element 70. The rotor122 is coupled with the head model 50.

Referring to FIG. 15, at step 420, data are collected from one or moresensors embedded inside or partially attached with the wall of the skullcomponent or located on a base support. At step 430, a plurality ofimages are taken using a high speed camera 76 to show one or morecomponents inside the interior chamber 85 before, during and/or afterimpact. At step 440, the data and the plurality of images are analyzedusing a computer and a computer program so as to detect impact inducedbrain trauma.

The present disclosure provides a good approach to examine the flow andpressurization of the cerebrospinal fluid flow (CSF) in the subarachnoidspace (SAS) as the head is exposed to sudden external impacts. The testapparatus or system includes an improved head model to better understandthe mechanism of concussive and sub-concussive brain injuries, and toprovide guidance for the prevention of such injuries. For example, theCSF flow through the soft, porous arachnoid trabeculae (AT) in the SAS,and both translational and rotational impact are considered. Withconsideration of the complicated nature of the biological system, abiomimetic approach is used to investigate the mechanism of brain injurywith more and better results.

The systems and the methods in the present disclosure are useful, forexample, in studying patient-specific pathology and designing productssuch as helmets to protect heads. For example, the apparatuses and themethods of the present disclosure can be used to provide predictableresults in locating the potential areas having brain injury. The braincomponent can be patient-specific based on CT scan data. The apparatusand the methods provide a cost-saving alternative to expensive magneticresonance imaging (MM). When a specific area for injury is identified,an MM can be used for further diagnosis. As another example, theapparatus and the methods in the present disclosure can be used fordesigning helmets or other head-protection products. Such a product canbe placed on a head model as described herein, and impact testing can beperformed. The results provide guidance for designing better products tominimize or eliminate brain injury.

A computer implemented program can be developed and used for collectingand analyzing the data and images. The methods and system describedherein may be at least partially embodied in the form ofcomputer-implemented processes and apparatus for practicing thoseprocesses. The disclosed methods may also be at least partially embodiedin the form of tangible, non-transient machine readable storage mediaencoded with computer program code. The media may include, for example,RAMs, ROMs, CD-ROMs, DVD-ROMs, BD-ROMs, hard disk drives, flashmemories, or any other non-transient machine-readable storage medium, orany combination of these mediums, wherein, when the computer programcode is loaded into and executed by a computer, the computer becomes anapparatus for practicing the method. The methods may also be at leastpartially embodied in the form of a computer into which computer programcode is loaded and/or executed, such that, the computer becomes anapparatus for practicing the methods. When implemented on ageneral-purpose processor, the computer program code segments configurethe processor to create specific logic circuits. The methods mayalternatively be at least partially embodied in a digital signalprocessor formed of application specific integrated circuits forperforming the methods.

Although the subject matter has been described in terms of exemplaryembodiments, it is not limited thereto. Rather, the appended claimsshould be construed broadly, to include other variants and embodiments,which may be made by those skilled in the art.

What is claimed is:
 1. A system for testing impact induced brain trauma,comprising: a head model comprising: a skull component having a walldefining an interior chamber, the wall comprising an exterior wallsurface and an interior wall surface; a brain component disposed withinthe interior chamber, the brain component comprising a gel material forsimulating brain tissue; a fluid component disposed inside the interiorchamber; and a fluid tank fluidly coupled with the skull component andconfigured to provide the fluid component into the interior chamber. 2.The system of claim 1, wherein the skull component is made of a rigidand transparent material.
 3. The system of claim 1, wherein the braincomponent is in a spherical shape, or is shaped and sized to simulate abrain of a human subject.
 4. The system of claim 1, wherein the fluidcomponent has at least one portion disposed between the brain componentand the interior wall surface of the skull component.
 5. The system ofclaim 1, wherein the fluid tank is connected with the skull componentthrough a tube and configured to adjust a pressure of the fluidcomponent inside the interior chamber.
 6. The system of claim 1, whereinthe head model further comprises: a layer of porous media disposedbetween the brain component and the interior wall surface of the skullcomponent.
 7. The system of claim 6, wherein the layer of porous mediacomprises the fluid component disposed inside the porous media.
 8. Thesystem of claim 1, further comprising: at least one impact elementconfigured to provide an impact on the head model, the impact beingtranslational or rotational or both.
 9. The system of claim 8, whereinthe at least one impact element comprises a rotor coupled with the headmodel to provide a rotational impact on the head model.
 10. The systemof claim 1, further comprising one or more sensors embedded inside orpartially attached with the wall of the skull component.
 11. The systemof claim 10, wherein the one or more sensors are selected from the groupconsisting of a pressure sensor, a displacement sensor, anaccelerometer, and a combination thereof.
 12. The system of claim 10,further comprising a camera configured to take a plurality of imagesshowing one or more components inside the interior chamber.
 13. Thesystem of claim 12, further comprising a computer and a computer programconfigured to analyze data from the one or more sensors and theplurality of the images for detecting impact induced brain trauma.
 14. Amethod of forming a system for testing impact induced brain trauma,comprising the step of forming a head model, wherein forming the headmodel comprises: providing a skull component having a wall defining aninterior chamber, the wall comprising an exterior wall surface and aninterior wall surface; forming a brain component, the brain componentcomprising a gel material for simulating brain tissues; placing thebrain component within the interior chamber; and supplying a fluidcomponent into the interior chamber from a fluid tank disposed outsidethe skull component and fluidly coupled with the skull component. 15.The method of claim 14, wherein the fluid tank is configured to providethe fluid component into the interior chamber with a controlledpressure.
 16. The method of claim 14, wherein the brain component isformed through steps including: three-dimensionally (3-D) printing askull model based on anatomical data from computed topography (CT) scanof a head of a human subject; forming a negative casting mold based onthe skull model; and casting the brain component inside the negativecasting mold.
 17. The method of claim 14, further comprising: placing alayer of porous media between the brain component and the interior wallsurface of the skull component.
 18. The method of claim 14, furthercomprising: providing at least one impact element configured to providean impact on the head model, the impact being translational orrotational or both.
 19. A method of using a system for testing impactinduced brain trauma, the system comprising: a head model comprising: askull component having a wall defining an interior chamber, the wallcomprising an exterior wall surface and an interior wall surface; abrain component disposed within the interior chamber, the braincomponent comprising a gel material for simulating brain tissues; afluid component disposed inside the interior chamber; and a fluid tankfluidly coupled with the skull component and configured to provide thefluid component into the interior chamber; wherein the method comprisesa step of providing an impact on the head model from at least one impactelement, the impact being translational or rotational or both.
 20. Themethod of claim 19, wherein the head model further comprises a layer ofporous media disposed between the brain component and the interior wallsurface of the skull component.
 21. The method of claim 19, wherein arotational impact on the head model is provided by a rotor in the atleast one impact element, the rotor coupled with the head model.
 22. Themethod of claim 19, further comprising: collecting data from one or moresensors embedded inside or partially attached with the wall of the skullcomponent; taking a plurality of images through a camera to show one ormore components inside the interior chamber; and analyzing the data andthe plurality of images using a computer and a computer program so as todetect impact induced brain trauma.